192 clutches and power-stop control – Clutches – Axially engaging
Reexamination Certificate
2000-04-20
2001-01-09
Lorence, Richard M. (Department: 3681)
192 clutches and power-stop control
Clutches
Axially engaging
C192S069420, C301S105100, C180S247000
Reexamination Certificate
active
06170628
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to transfer of torque between components of a vehicle drive line (sometimes referred to as a drive train) exemplified by the automated engagement/disengagement of a wheel to a vehicle's drive line.
BACKGROUND OF THE INVENTION
A common drive system for certain types of vehicles includes the ability to shift from two-wheel drive to four-wheel drive. Either the front wheels or the back wheels are permanently engaged with the vehicle's drive train and the remaining set of wheels is shifted into and out of engagement with the drive train. For purposes of discussion, the rear wheels will hereafter be considered permanently engaged with the drive train and the front wheels are in part-time engagement, but the reader will appreciate that the invention is equally applicable to the front wheels being permanently engaged with a drive train and the rear wheels in part-time engagement.
Whereas a drive train will include a transmission that transmits drive power from the vehicle's engine to a propeller shaft that extends to the differential and then the wheel axles, e.g, of the rear wheels, in order to provide four-wheel drive, there is a further propeller shaft that extends forward to the differential of the front wheels, e.g., via a transfer case that also receives drive power from the transmission. A shift mechanism in the transfer case engages and disengages the drive power to the propeller shaft for the front wheels.
In the disengaged position, the front wheels are not being driven but then the passive turning of the front wheels drives the front wheel axles and front wheel propeller shaft unless there is also a disconnect mechanism between each front wheel and its axle. It is the disconnect mechanism between the wheel and axle to which the present invention is primarily directed although those skilled in the art will appreciate the further application of the invention, e.g., to other components of the drive train.
Returning to the front wheel connect/disconnect mechanism, historically this mechanism was located in the wheel hub and advanced from manual to automatic operation. The structural arrangement included a cylindrically configured spindle which was fixedly mounted to the vehicle chassis, i.e., on the steering knuckle. The axle protruded through the center of the spindle and a wheel hub was mounted on the exterior of the spindle and surrounding the axle. Each of the wheel hub and axle was independently rotatable relative to the spindle and a clutch mechanism at the outboard end of the spindle produced the desired connect/disconnect of the wheel hub to the axle. A later version referred to as a live spindle provided for the spindle to be rotatably mounted to the vehicle chassis and the wheel hub was fixedly mounted to the spindle. The axle as before was protruded through the spindle and a clutch mechanism at the outboard end of the spindle produced the connect/disconnect operation.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
In the ongoing development of clutch mechanism and particularly as related to automatically actuated clutch mechanism, several factors remained a concern. The material of the various clutch components being extended to the outboard end of the spindle added weight and enlarged the king pin radius, both of which are undesirable. Also, the components had to be packaged to fit within the confined space of the wheel hub interior and as concerns the live spindle version, all of the components for automatic actuation of a clutch mechanism had to be mounted on a rotating member, i.e., the rotating wheel hub, the rotating spindle or the rotating axle. Whereas hydraulic and pneumatic automatic actuating devices were developed, such relied on creating a sealed chamber as between two relatively rotating components and such chambers were subject to undesired leakage.
The present invention obviates much or all of these deficiencies by the strategic placement of the clutch mechanism at the inboard end of the spindle. In the preferred embodiment, the axle and spindle are cooperatively configured to provide mated and adjacent spline portions at circumferentially exterior locations adjacent to a non-rotating portion of the chassis, e.g., the knuckle. The automatic actuation mechanism is fixedly mounted to the knuckle and the rotating clutch ring is axially displaced through a bearing interface between the actuator and the clutch ring.
Whereas the above substantially describes the structure of parent U.S. patent application Ser. No. 08/651,384 referred to above, a number of improvements are herein additionally disclosed. The structure as described above readily adapts to other drive train types, e.g., wherein the front wheels are permanently engaged with the front axles in full time four-wheel drive, and wherein the front wheels are permanently disengaged from the drive train in two-wheel drive only. Thus, widely varying wheel end designs for different drive train types can be avoided. A further improvement includes multiple sensors to provide feed back for ABS braking as well as other sensing needs, e.g., determining whether the clutch is engaged or disengaged. The reduced mechanism between the knuckle and wheel hub (outboard of the clutch mechanism) allows a shorter distance between the load center of the wheel hub (tire) and the king pin axis and a reduced mass for the axle end (resulting in weight reduction). The allowable increased circumference of the clutch ring and thus a greater number of splines (because it is not confined to the wheel hub) enables shorter overlap of the clutch ring splines with the splines of the axle and wheel hub, again shortening the axial depth of the clutch mechanism. Also, part of the new disclosure is improved forms of bearing members (cartridge type, ball type, split bearing with one bearing half attached by fastener or press fit into the knuckle, etc.) which provides more efficient assembly of the clutch components as well as improved performance.
REFERENCES:
patent: 2978276 (1961-04-01), Huffman
patent: 3718213 (1973-02-01), Hegar
patent: 4116320 (1978-09-01), Quillam
patent: 4213514 (1980-07-01), Ehringer
patent: 4273460 (1981-06-01), Ueno
patent: 4282949 (1981-08-01), Kopich et al.
patent: 4441597 (1984-04-01), Teraoka
patent: 4561520 (1985-12-01), Fogelberg
patent: 4627512 (1986-12-01), Clohessy
patent: 4692049 (1987-09-01), Engle
patent: 4775040 (1988-10-01), Telford
patent: 4817752 (1989-04-01), Lobo et al.
patent: 4893960 (1990-01-01), Beier
patent: 4960192 (1990-10-01), Kurihara
patent: 5044479 (1991-09-01), Petrak
patent: 5141088 (1992-08-01), Kurihara
patent: 5353890 (1994-10-01), Clohessy
patent: 5394967 (1995-03-01), Bigley
patent: 5702162 (1997-12-01), Pressler
patent: 5740895 (1998-04-01), Bigley
patent: 5984422 (1999-11-01), Seifert
Harrington Robert L.
Lorence Richard M.
Warn Industries, Inc.
LandOfFree
Vehicle drive train does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vehicle drive train, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vehicle drive train will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2483982